Known Bugs

There are a number of glitches that people have discovered in the Halo:
Reach game system. This article will cover only those dealing with the
spawn engine that have been confirmed by hard evidence in controlled
test cases.

A bug is defined as a behavior that contradicts official documentation. What
is described here are behaviors that can consistently be reproduced,
and contradict Bungie published materials. If Bungie does not describe a
behavior, then any behavior would be correct (not a bug) and
technically considered undefined.

There may be cases where what appears to be a bug is not a bug at all,
but a design decision. But without clarification from Bungie (or 343i in
the future), such behaviors should be classified as unintended behavior
- bugs.

For the purposes of this article, Respawn Zone will be referred to as
Strong Zone, Weak Respawn Zone will be referred to as Weak Zone, Anti
Respawn Zone will be referred to as Anti Zone, and the general case of
any of these three will be referred to as Respawn Zone collectively.

Infection Initial Load Out Cameras Are Inconsistent

For Infection game type variants, the initial load out cameras are
inconsistent through out the game. Each round starts with an initial
load out camera. But the initial load out cameras used for round one are
not the same as those used for the other rounds.

For round one, the blue and red team assigned initial load out cameras
are used, red for humans, blue for zombies. For all other rounds, a
neutral team assigned initial load out camera is used.

This inconsistency gives a map the appearance of lacking quality of craftsmanship.

Test Case

Setup three initial load out cameras, assign them to red, blue and
neutral teams respectively. Run an Infection game through all rounds.
Note which cameras are used at the start of each round.

Work Around

There are two work arounds.

(1) Ensure all three cameras are in an identical position and orientation (they all see the same thing).

(2) Use only a single neutral team assigned camera.

More Information

Because Bungie maps fail to demonstrate the problem, they obviously
employed one of the work arounds. We can assume this is a known bug.

If you want to use team assigned cameras for other game types (e.g.,
Slayer, Bomb, Flag, etc.) for the different teams, but you do not want
to use those cameras in Infection, then assign those cameras to
TEAM_ONLY. This game type label will not match with Infection and the
team assigned cameras will not spawn on the map for Infection game
types.[1]

If you want to use a different neutral team assigned camera for FFA
games, then assign it to FFA_ONLY. Again, this game type label will not
match with Infection and the FFA camera will not spawn on the map for
Infection game types.[1]

KOTH & Territories Disrespect Anti Respawn Zone

If you have a map with Anti Respawn Zones, those zones are ignored when
KOTH and Territories game type variants are used. It is as though they
were never present.

Test Case

Two test cases were used to prove the bug out. I will outline only one of them.

The test case involved three Respawn Points, A, B, and C. A neutral
Respawn Zone encompasses all three Respawn Points. B is covered with two
Anti Respawn Zones, and C is covered with only one Anti Respawn Zone. A
crate obstacle would spawn on the map over A after a period of time to
obstruct A and force the use of B or C. The player would spawn and
either move toward or fall into a teleport. At the other teleport on the
other side of Forge World, the player would be in a Kill Boundary and
immediately die.

Various game types were tested on the map. For all but KOTH and
Territories variants, the player would only spawn on A, because the Anti
Respawn Zones would lead to A being favored every time.

Once the obstacle spawned, the player would spawn only at C, since C was favored by having less Anti Respawn Zones.

However, for KOTH and for Territories variants, the player would spawn
at any of the three Respawn Points, until A became obstructed. This
showed that the problem was not a failure to combine Anti Respawn Zones,
but a failure to even use them in weighting of the Respawn Points.

Speculation

This bug probably got by Bungie, because Anti Respawn Zones are very
unusual in any map. If they knew about this bug, they probably decided
it was a low priority bug, since most maps do not use Anti Respawn
Zones.

Work Around

There is no known work around at this time.

Acknowledgments

Thanks to dt192 for finding this bug, bringing it to my attention, and then helping me characterize this bug by doing a lot of testing.

Stock Pile Disrespects Respawn Zone Game Type Labels

If you have a map with Strong Zones for various game types, you will
assign the Strong Zones' Game Type Labels to specific game types, such
as CTF, SLAYER, TEAM_ONLY, FFA_ONLY, ASSAULT, etc. The Stock Pile game
type has been demonstrated to enable every Strong Zone, regardless of
their game type label. This presents problems for those maps that use
anything other than the simple Strong Zone model of splitting the map in
half and assigning each half to the two teams, red and blue.

Imagine a simple, yet common case, of a neutral Strong Zone covering the
whole map and assigned to FFA_ONLY. This Strong Zone, when enabled in
Stock Pile, would enable a team member to spawn anywhere on the map
where a neutral Respawn Point is located, even at the enemy's stock pile
collection zone.

Test Case

The test case involved a number of small Strong Zones with a Respawn
Point in each and a control Respawn Point outside of all Strong Zones.
When the player was killed, he respawned in any of the Strong Zones as
though they were all enabled. He never respawned in the controlled
Respawn Point unless all other Respawn Points were obstructed. The
death influencer never overcame any of the Strong Zones, confirming the
Strong Zones' basic behavior.

Speculation

This bug in the game type script (if that is where the bug is at) may be
the reason that the engineers chose to create a red and a blue team
assigned Strong Zone centered at the two teams' respective drop zones.
Their engineers may not have known what was causing the problem and they
may have speculated that creating Strong Zones might alleviate the
problem. If this is the genesis of the built in Strong Zones, then they
only complicated the matter further.

More Information

The article Respawn Zone Anomalies talks more about the Stock Pile's built in Strong Zones and how they interfere with other game types on the same map.

Work Around

There are a number of work arounds, depending upon your particular map.
But the most general work around is to use only one blue team Strong
Zone and one red team Strong Zone and divide the map in half with those
two zones. Then, make certain that the Stock Pile drop zones are far
enough away (15 units radius for each, 30 units from zone to zone) from
the other team's Strong Zone that it won't overlap at all.

Too Many Respawn Zones Breaks Respawn Zone Behavior

It has been demonstrated that after laying down all of the Weak Zones or
all of the Anti Zones, then laying down a Strong Zone, that the Strong
Zone ceases to function at all. Bungie suggested that the problem was
likely in a collection object within the software and that Bungie never
intended to have many Weak or Anti Zones used in the manner described.

Test Case

All Weak Zones were laid down (it doesn't matter where - they can occupy
the same volume if you wish). then a Strong Zone was placed on the map
else where. A Respawn Point was placed in the Strong Zone and a control
Respawn Point was placed outside of all Respawn Zones.

The player was killed at the Respawn Point in the Strong Zone and
respawned at the control Respawn Point. If the Strong Zone had been
functioning correctly, the player would exclusively Respawned in the
Strong Zone only.

The Strong Zone was deleted. This was followed by deleting of all the
Weak or Anti Strong zones, save five. Then the Strong Zone was added
back onto the map as before.

The player was killed at the Respawn Point in the Strong Zone and
respawned consistently withn the Stong Zone. This demonstrated that the
Strong Zone was functioning as intended.

Speculation

This bug must be analyzed by 343i, as Bungie is not going to take the
time. But it appears that the Spawn Engine of Halo: Reach will only look
so far deep into the Respawn Zone collection object (if that is the
actual software architecture) before it stops looking for Strong Zones
to enforce in the game play.

Work Around

The best advise is to avoid using Weak and Anti Zones, or to limit them
to one or two per team at most. Ultimately, if you use even one Weak or
Anti Zone, you should be fully aware of what you are doing, because you
are altering the Spawn Engine's algorithms significantly.

Additionally, always lay the Strong Zones down first. It is believed
that the problem is due to traversing a collection object that holds all
of the various Respawn Zones. If the Strong Zones are at the front of
the list, then they should all get processed correctly. Again, this is
based upon an assumption made from a statement by JonnyOThan and is not
confirmed.

Line Of Sight Overcomes Strong Zones

It was discovered that weapon line of sight (LOS) can overcome the
Strong Zone. It takes very specific conditions. But what makes this a
bug is that JonnyOThan was puzzled by it when I brought this to his
attention. He never officially declared it was a bug, but he spent
enough effort trying to reproduce it that he clearly was taken by
surprise by it - that is, he never heard anyone within Bungie describe
the behavior as intended. Nevertheless, it is very possible that someone
within Bungie actually intended the behavior to occur. This is why it
is critical to always have the authoritative voice officially explain
what it is we are seeing.

Test Case

Lay down two control Respawn Points outside the Strong Zone and one
inside the Strong Zone. Kill the player and train a sniper on the
Respawn Point inside the Strong Zone. The player will respawn at one of
the two control Respawn Points. This demonstrates that the Strong Zone
no longer was capable of maintaining a weight on the Respawn Point
within the Strong Zone when LOS was applied, and the control Respawn
Points had the greater weight.

Kill the player and keep LOS away from all Respawn Points. Even when the
death influencer is centered over the Respawn Point within the Strong
Zone, the player will always respawn at the Respawn Point in the Strong
Zone. The Strong Zone is applying so much positive weight to the Respawn
Point that the player has no choice but to respawn at that Respawn
Point.

Remove one of the control Respawn Points and repeat the test. At no time
will the player respawn anywhere but within the Strong Zone. This shows
that the LOS does not overcome the Strong Zone when configured with as
many or more Respawn Points inside the Strong Zone as outside.

Make sure the following conditions are met, and the LOS influencer
should never cause a player to spawn outside his team's Strong Zone.

1. Have so many Respawn Points laid within a team's Strong Zone that
there is no way they can all become obstructed and influenced by LOS
simultaneously. This will ensure that at least one Respawn point is
available for spawning within the Strong Zone.

2. Ensure that the number of neutral and team assigned Respawn Points
outside a team's Strong Zone is less than the number of neutral and team
assigned Respawn Points inside the team's Strong Zone. (Of course, you
would never have team assigned Respawn Points outside the team's Respawn
Zone, but for completeness I needed to add it here. If you do have team
assigned Respawn Points outside the team's Respawn Zone, they would
appear incorrect during map analysis, but would actually contribute to
the total count of Respawn Points available for the team outside their
Respawn Zone.)

Anti Zones Do Combine Without Strong Zone

Bungie documentation states that Anti Zones do not combine with each
other unless within a Strong Zone. Tests have demonstrated a behavior
that appears to contradict the documented behavior. This has yet to be
confirmed in any way by Bungie or 343i.

Test Case

Combine 10 Anti Zones over a Respawn Point. Set another Anti Zone some
distance away with another Respawn Point. Kill the player that spawns at
either Respawn Point. Notice that the player will spawn at each, but
will spawn more often where there is only one Anti Zone than multiple
Anti Zones. The death influencer will drive the player to the other
Respawn Point, but the fact that there is a tendency to favor the single
Anti Zone strongly suggest that Anti Zones do combine in the absence of
Strong Zones.

Work Around

There is no work around, just an awareness of how the bug manifests.
Just don't overlap Anti Zones if you don't want them to combine.

Invasion Slayer Fire Team Assignments Not Honored

The
invasion slayer setup article from Bungie states that respawn zones
honor fire teams. Testing shows this is not true (that a player can
respawn in any fire team respawn zone). It is not clear if the
documentation is incorrect or if there
is a bug in the Spawn Engine. For this bug, Invasion Respawn Zone is any
object with a volume (I suggest a hill marker) with the game type label INV_SLAYER_RES_ZONE.

Test Case

Setup a map to work with Invasion Slayer. Create three Invasion Respawn
Zones, and assign each to a unique fire team. Spawn Sequence = 0 for
Fire Team 1, 1 for Fire Team 2, and 2 for Fire Team 3. Spawn Sequence = 3
is for all Fire Teams and is not part of this test configuration.

Play the game and kill a player. You will see that they can choose any of the three Invasion Respawn Zones.

Work Around

None at this time.

Invasion Initial Spawns Honor Fire Teams

According to Bungie, Initial Spawns for Invasion do not honor Fire
Teams. Yet, the Initial Spawns on all Bungie Invasion maps were setup
to honor Fire Teams and tests tend to support the conclusion (though
empirical evidence is in and of itself inconclusive) that Fire Teams are
in fact honored.

This is classified as a documentation error and not a bug.

Test Case

The test case is already provided by Bungie maps.

More Information

It is assumed that the article was in error, and that the Bungie maps
demonstrate the intended use of Initial Spawn Points' Fire Team
assignments.

Work Around

None

Summary

These are the known spawning bugs with the Halo: Reach engine. It is my hope that 343i will look at this article and improve Halo:
Reach by fixing these bugs. While these bugs represent corner cases,
they also represent cases that have been encountered by forgers in the
community in the course of forging maps (as opposed to forgers
specifically looking for bugs).